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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * linux/drivers/clocksource/arm_arch_timer.c
4 *
5 * Copyright (C) 2011 ARM Ltd.
6 * All Rights Reserved
7 */
8
9#define pr_fmt(fmt) "arch_timer: " fmt
10
11#include <linux/init.h>
12#include <linux/kernel.h>
13#include <linux/device.h>
14#include <linux/smp.h>
15#include <linux/cpu.h>
16#include <linux/cpu_pm.h>
17#include <linux/clockchips.h>
18#include <linux/clocksource.h>
19#include <linux/clocksource_ids.h>
20#include <linux/interrupt.h>
21#include <linux/kstrtox.h>
22#include <linux/of_irq.h>
23#include <linux/of_address.h>
24#include <linux/io.h>
25#include <linux/slab.h>
26#include <linux/sched/clock.h>
27#include <linux/sched_clock.h>
28#include <linux/acpi.h>
29#include <linux/arm-smccc.h>
30#include <linux/ptp_kvm.h>
31
32#include <asm/arch_timer.h>
33#include <asm/virt.h>
34
35#include <clocksource/arm_arch_timer.h>
36
37#define CNTTIDR 0x08
38#define CNTTIDR_VIRT(n) (BIT(1) << ((n) * 4))
39
40#define CNTACR(n) (0x40 + ((n) * 4))
41#define CNTACR_RPCT BIT(0)
42#define CNTACR_RVCT BIT(1)
43#define CNTACR_RFRQ BIT(2)
44#define CNTACR_RVOFF BIT(3)
45#define CNTACR_RWVT BIT(4)
46#define CNTACR_RWPT BIT(5)
47
48#define CNTPCT_LO 0x00
49#define CNTVCT_LO 0x08
50#define CNTFRQ 0x10
51#define CNTP_CVAL_LO 0x20
52#define CNTP_CTL 0x2c
53#define CNTV_CVAL_LO 0x30
54#define CNTV_CTL 0x3c
55
56/*
57 * The minimum amount of time a generic counter is guaranteed to not roll over
58 * (40 years)
59 */
60#define MIN_ROLLOVER_SECS (40ULL * 365 * 24 * 3600)
61
62static unsigned arch_timers_present __initdata;
63
64struct arch_timer {
65 void __iomem *base;
66 struct clock_event_device evt;
67};
68
69static struct arch_timer *arch_timer_mem __ro_after_init;
70
71#define to_arch_timer(e) container_of(e, struct arch_timer, evt)
72
73static u32 arch_timer_rate __ro_after_init;
74static int arch_timer_ppi[ARCH_TIMER_MAX_TIMER_PPI] __ro_after_init;
75
76static const char *arch_timer_ppi_names[ARCH_TIMER_MAX_TIMER_PPI] = {
77 [ARCH_TIMER_PHYS_SECURE_PPI] = "sec-phys",
78 [ARCH_TIMER_PHYS_NONSECURE_PPI] = "phys",
79 [ARCH_TIMER_VIRT_PPI] = "virt",
80 [ARCH_TIMER_HYP_PPI] = "hyp-phys",
81 [ARCH_TIMER_HYP_VIRT_PPI] = "hyp-virt",
82};
83
84static struct clock_event_device __percpu *arch_timer_evt;
85
86static enum arch_timer_ppi_nr arch_timer_uses_ppi __ro_after_init = ARCH_TIMER_VIRT_PPI;
87static bool arch_timer_c3stop __ro_after_init;
88static bool arch_timer_mem_use_virtual __ro_after_init;
89static bool arch_counter_suspend_stop __ro_after_init;
90#ifdef CONFIG_GENERIC_GETTIMEOFDAY
91static enum vdso_clock_mode vdso_default = VDSO_CLOCKMODE_ARCHTIMER;
92#else
93static enum vdso_clock_mode vdso_default = VDSO_CLOCKMODE_NONE;
94#endif /* CONFIG_GENERIC_GETTIMEOFDAY */
95
96static cpumask_t evtstrm_available = CPU_MASK_NONE;
97static bool evtstrm_enable __ro_after_init = IS_ENABLED(CONFIG_ARM_ARCH_TIMER_EVTSTREAM);
98
99static int __init early_evtstrm_cfg(char *buf)
100{
101 return kstrtobool(buf, &evtstrm_enable);
102}
103early_param("clocksource.arm_arch_timer.evtstrm", early_evtstrm_cfg);
104
105/*
106 * Makes an educated guess at a valid counter width based on the Generic Timer
107 * specification. Of note:
108 * 1) the system counter is at least 56 bits wide
109 * 2) a roll-over time of not less than 40 years
110 *
111 * See 'ARM DDI 0487G.a D11.1.2 ("The system counter")' for more details.
112 */
113static int arch_counter_get_width(void)
114{
115 u64 min_cycles = MIN_ROLLOVER_SECS * arch_timer_rate;
116
117 /* guarantee the returned width is within the valid range */
118 return clamp_val(ilog2(min_cycles - 1) + 1, 56, 64);
119}
120
121/*
122 * Architected system timer support.
123 */
124
125static __always_inline
126void arch_timer_reg_write(int access, enum arch_timer_reg reg, u64 val,
127 struct clock_event_device *clk)
128{
129 if (access == ARCH_TIMER_MEM_PHYS_ACCESS) {
130 struct arch_timer *timer = to_arch_timer(clk);
131 switch (reg) {
132 case ARCH_TIMER_REG_CTRL:
133 writel_relaxed((u32)val, timer->base + CNTP_CTL);
134 break;
135 case ARCH_TIMER_REG_CVAL:
136 /*
137 * Not guaranteed to be atomic, so the timer
138 * must be disabled at this point.
139 */
140 writeq_relaxed(val, timer->base + CNTP_CVAL_LO);
141 break;
142 default:
143 BUILD_BUG();
144 }
145 } else if (access == ARCH_TIMER_MEM_VIRT_ACCESS) {
146 struct arch_timer *timer = to_arch_timer(clk);
147 switch (reg) {
148 case ARCH_TIMER_REG_CTRL:
149 writel_relaxed((u32)val, timer->base + CNTV_CTL);
150 break;
151 case ARCH_TIMER_REG_CVAL:
152 /* Same restriction as above */
153 writeq_relaxed(val, timer->base + CNTV_CVAL_LO);
154 break;
155 default:
156 BUILD_BUG();
157 }
158 } else {
159 arch_timer_reg_write_cp15(access, reg, val);
160 }
161}
162
163static __always_inline
164u32 arch_timer_reg_read(int access, enum arch_timer_reg reg,
165 struct clock_event_device *clk)
166{
167 u32 val;
168
169 if (access == ARCH_TIMER_MEM_PHYS_ACCESS) {
170 struct arch_timer *timer = to_arch_timer(clk);
171 switch (reg) {
172 case ARCH_TIMER_REG_CTRL:
173 val = readl_relaxed(timer->base + CNTP_CTL);
174 break;
175 default:
176 BUILD_BUG();
177 }
178 } else if (access == ARCH_TIMER_MEM_VIRT_ACCESS) {
179 struct arch_timer *timer = to_arch_timer(clk);
180 switch (reg) {
181 case ARCH_TIMER_REG_CTRL:
182 val = readl_relaxed(timer->base + CNTV_CTL);
183 break;
184 default:
185 BUILD_BUG();
186 }
187 } else {
188 val = arch_timer_reg_read_cp15(access, reg);
189 }
190
191 return val;
192}
193
194static notrace u64 arch_counter_get_cntpct_stable(void)
195{
196 return __arch_counter_get_cntpct_stable();
197}
198
199static notrace u64 arch_counter_get_cntpct(void)
200{
201 return __arch_counter_get_cntpct();
202}
203
204static notrace u64 arch_counter_get_cntvct_stable(void)
205{
206 return __arch_counter_get_cntvct_stable();
207}
208
209static notrace u64 arch_counter_get_cntvct(void)
210{
211 return __arch_counter_get_cntvct();
212}
213
214/*
215 * Default to cp15 based access because arm64 uses this function for
216 * sched_clock() before DT is probed and the cp15 method is guaranteed
217 * to exist on arm64. arm doesn't use this before DT is probed so even
218 * if we don't have the cp15 accessors we won't have a problem.
219 */
220u64 (*arch_timer_read_counter)(void) __ro_after_init = arch_counter_get_cntvct;
221EXPORT_SYMBOL_GPL(arch_timer_read_counter);
222
223static u64 arch_counter_read(struct clocksource *cs)
224{
225 return arch_timer_read_counter();
226}
227
228static u64 arch_counter_read_cc(const struct cyclecounter *cc)
229{
230 return arch_timer_read_counter();
231}
232
233static struct clocksource clocksource_counter = {
234 .name = "arch_sys_counter",
235 .id = CSID_ARM_ARCH_COUNTER,
236 .rating = 400,
237 .read = arch_counter_read,
238 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
239};
240
241static struct cyclecounter cyclecounter __ro_after_init = {
242 .read = arch_counter_read_cc,
243};
244
245struct ate_acpi_oem_info {
246 char oem_id[ACPI_OEM_ID_SIZE + 1];
247 char oem_table_id[ACPI_OEM_TABLE_ID_SIZE + 1];
248 u32 oem_revision;
249};
250
251#ifdef CONFIG_FSL_ERRATUM_A008585
252/*
253 * The number of retries is an arbitrary value well beyond the highest number
254 * of iterations the loop has been observed to take.
255 */
256#define __fsl_a008585_read_reg(reg) ({ \
257 u64 _old, _new; \
258 int _retries = 200; \
259 \
260 do { \
261 _old = read_sysreg(reg); \
262 _new = read_sysreg(reg); \
263 _retries--; \
264 } while (unlikely(_old != _new) && _retries); \
265 \
266 WARN_ON_ONCE(!_retries); \
267 _new; \
268})
269
270static u64 notrace fsl_a008585_read_cntpct_el0(void)
271{
272 return __fsl_a008585_read_reg(cntpct_el0);
273}
274
275static u64 notrace fsl_a008585_read_cntvct_el0(void)
276{
277 return __fsl_a008585_read_reg(cntvct_el0);
278}
279#endif
280
281#ifdef CONFIG_HISILICON_ERRATUM_161010101
282/*
283 * Verify whether the value of the second read is larger than the first by
284 * less than 32 is the only way to confirm the value is correct, so clear the
285 * lower 5 bits to check whether the difference is greater than 32 or not.
286 * Theoretically the erratum should not occur more than twice in succession
287 * when reading the system counter, but it is possible that some interrupts
288 * may lead to more than twice read errors, triggering the warning, so setting
289 * the number of retries far beyond the number of iterations the loop has been
290 * observed to take.
291 */
292#define __hisi_161010101_read_reg(reg) ({ \
293 u64 _old, _new; \
294 int _retries = 50; \
295 \
296 do { \
297 _old = read_sysreg(reg); \
298 _new = read_sysreg(reg); \
299 _retries--; \
300 } while (unlikely((_new - _old) >> 5) && _retries); \
301 \
302 WARN_ON_ONCE(!_retries); \
303 _new; \
304})
305
306static u64 notrace hisi_161010101_read_cntpct_el0(void)
307{
308 return __hisi_161010101_read_reg(cntpct_el0);
309}
310
311static u64 notrace hisi_161010101_read_cntvct_el0(void)
312{
313 return __hisi_161010101_read_reg(cntvct_el0);
314}
315
316static struct ate_acpi_oem_info hisi_161010101_oem_info[] = {
317 /*
318 * Note that trailing spaces are required to properly match
319 * the OEM table information.
320 */
321 {
322 .oem_id = "HISI ",
323 .oem_table_id = "HIP05 ",
324 .oem_revision = 0,
325 },
326 {
327 .oem_id = "HISI ",
328 .oem_table_id = "HIP06 ",
329 .oem_revision = 0,
330 },
331 {
332 .oem_id = "HISI ",
333 .oem_table_id = "HIP07 ",
334 .oem_revision = 0,
335 },
336 { /* Sentinel indicating the end of the OEM array */ },
337};
338#endif
339
340#ifdef CONFIG_ARM64_ERRATUM_858921
341static u64 notrace arm64_858921_read_cntpct_el0(void)
342{
343 u64 old, new;
344
345 old = read_sysreg(cntpct_el0);
346 new = read_sysreg(cntpct_el0);
347 return (((old ^ new) >> 32) & 1) ? old : new;
348}
349
350static u64 notrace arm64_858921_read_cntvct_el0(void)
351{
352 u64 old, new;
353
354 old = read_sysreg(cntvct_el0);
355 new = read_sysreg(cntvct_el0);
356 return (((old ^ new) >> 32) & 1) ? old : new;
357}
358#endif
359
360#ifdef CONFIG_SUN50I_ERRATUM_UNKNOWN1
361/*
362 * The low bits of the counter registers are indeterminate while bit 10 or
363 * greater is rolling over. Since the counter value can jump both backward
364 * (7ff -> 000 -> 800) and forward (7ff -> fff -> 800), ignore register values
365 * with all ones or all zeros in the low bits. Bound the loop by the maximum
366 * number of CPU cycles in 3 consecutive 24 MHz counter periods.
367 */
368#define __sun50i_a64_read_reg(reg) ({ \
369 u64 _val; \
370 int _retries = 150; \
371 \
372 do { \
373 _val = read_sysreg(reg); \
374 _retries--; \
375 } while (((_val + 1) & GENMASK(8, 0)) <= 1 && _retries); \
376 \
377 WARN_ON_ONCE(!_retries); \
378 _val; \
379})
380
381static u64 notrace sun50i_a64_read_cntpct_el0(void)
382{
383 return __sun50i_a64_read_reg(cntpct_el0);
384}
385
386static u64 notrace sun50i_a64_read_cntvct_el0(void)
387{
388 return __sun50i_a64_read_reg(cntvct_el0);
389}
390#endif
391
392#ifdef CONFIG_ARM_ARCH_TIMER_OOL_WORKAROUND
393DEFINE_PER_CPU(const struct arch_timer_erratum_workaround *, timer_unstable_counter_workaround);
394EXPORT_SYMBOL_GPL(timer_unstable_counter_workaround);
395
396static atomic_t timer_unstable_counter_workaround_in_use = ATOMIC_INIT(0);
397
398/*
399 * Force the inlining of this function so that the register accesses
400 * can be themselves correctly inlined.
401 */
402static __always_inline
403void erratum_set_next_event_generic(const int access, unsigned long evt,
404 struct clock_event_device *clk)
405{
406 unsigned long ctrl;
407 u64 cval;
408
409 ctrl = arch_timer_reg_read(access, ARCH_TIMER_REG_CTRL, clk);
410 ctrl |= ARCH_TIMER_CTRL_ENABLE;
411 ctrl &= ~ARCH_TIMER_CTRL_IT_MASK;
412
413 if (access == ARCH_TIMER_PHYS_ACCESS) {
414 cval = evt + arch_counter_get_cntpct_stable();
415 write_sysreg(cval, cntp_cval_el0);
416 } else {
417 cval = evt + arch_counter_get_cntvct_stable();
418 write_sysreg(cval, cntv_cval_el0);
419 }
420
421 arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl, clk);
422}
423
424static __maybe_unused int erratum_set_next_event_virt(unsigned long evt,
425 struct clock_event_device *clk)
426{
427 erratum_set_next_event_generic(ARCH_TIMER_VIRT_ACCESS, evt, clk);
428 return 0;
429}
430
431static __maybe_unused int erratum_set_next_event_phys(unsigned long evt,
432 struct clock_event_device *clk)
433{
434 erratum_set_next_event_generic(ARCH_TIMER_PHYS_ACCESS, evt, clk);
435 return 0;
436}
437
438static const struct arch_timer_erratum_workaround ool_workarounds[] = {
439#ifdef CONFIG_FSL_ERRATUM_A008585
440 {
441 .match_type = ate_match_dt,
442 .id = "fsl,erratum-a008585",
443 .desc = "Freescale erratum a005858",
444 .read_cntpct_el0 = fsl_a008585_read_cntpct_el0,
445 .read_cntvct_el0 = fsl_a008585_read_cntvct_el0,
446 .set_next_event_phys = erratum_set_next_event_phys,
447 .set_next_event_virt = erratum_set_next_event_virt,
448 },
449#endif
450#ifdef CONFIG_HISILICON_ERRATUM_161010101
451 {
452 .match_type = ate_match_dt,
453 .id = "hisilicon,erratum-161010101",
454 .desc = "HiSilicon erratum 161010101",
455 .read_cntpct_el0 = hisi_161010101_read_cntpct_el0,
456 .read_cntvct_el0 = hisi_161010101_read_cntvct_el0,
457 .set_next_event_phys = erratum_set_next_event_phys,
458 .set_next_event_virt = erratum_set_next_event_virt,
459 },
460 {
461 .match_type = ate_match_acpi_oem_info,
462 .id = hisi_161010101_oem_info,
463 .desc = "HiSilicon erratum 161010101",
464 .read_cntpct_el0 = hisi_161010101_read_cntpct_el0,
465 .read_cntvct_el0 = hisi_161010101_read_cntvct_el0,
466 .set_next_event_phys = erratum_set_next_event_phys,
467 .set_next_event_virt = erratum_set_next_event_virt,
468 },
469#endif
470#ifdef CONFIG_ARM64_ERRATUM_858921
471 {
472 .match_type = ate_match_local_cap_id,
473 .id = (void *)ARM64_WORKAROUND_858921,
474 .desc = "ARM erratum 858921",
475 .read_cntpct_el0 = arm64_858921_read_cntpct_el0,
476 .read_cntvct_el0 = arm64_858921_read_cntvct_el0,
477 .set_next_event_phys = erratum_set_next_event_phys,
478 .set_next_event_virt = erratum_set_next_event_virt,
479 },
480#endif
481#ifdef CONFIG_SUN50I_ERRATUM_UNKNOWN1
482 {
483 .match_type = ate_match_dt,
484 .id = "allwinner,erratum-unknown1",
485 .desc = "Allwinner erratum UNKNOWN1",
486 .read_cntpct_el0 = sun50i_a64_read_cntpct_el0,
487 .read_cntvct_el0 = sun50i_a64_read_cntvct_el0,
488 .set_next_event_phys = erratum_set_next_event_phys,
489 .set_next_event_virt = erratum_set_next_event_virt,
490 },
491#endif
492#ifdef CONFIG_ARM64_ERRATUM_1418040
493 {
494 .match_type = ate_match_local_cap_id,
495 .id = (void *)ARM64_WORKAROUND_1418040,
496 .desc = "ARM erratum 1418040",
497 .disable_compat_vdso = true,
498 },
499#endif
500};
501
502typedef bool (*ate_match_fn_t)(const struct arch_timer_erratum_workaround *,
503 const void *);
504
505static
506bool arch_timer_check_dt_erratum(const struct arch_timer_erratum_workaround *wa,
507 const void *arg)
508{
509 const struct device_node *np = arg;
510
511 return of_property_read_bool(np, wa->id);
512}
513
514static
515bool arch_timer_check_local_cap_erratum(const struct arch_timer_erratum_workaround *wa,
516 const void *arg)
517{
518 return this_cpu_has_cap((uintptr_t)wa->id);
519}
520
521
522static
523bool arch_timer_check_acpi_oem_erratum(const struct arch_timer_erratum_workaround *wa,
524 const void *arg)
525{
526 static const struct ate_acpi_oem_info empty_oem_info = {};
527 const struct ate_acpi_oem_info *info = wa->id;
528 const struct acpi_table_header *table = arg;
529
530 /* Iterate over the ACPI OEM info array, looking for a match */
531 while (memcmp(info, &empty_oem_info, sizeof(*info))) {
532 if (!memcmp(info->oem_id, table->oem_id, ACPI_OEM_ID_SIZE) &&
533 !memcmp(info->oem_table_id, table->oem_table_id, ACPI_OEM_TABLE_ID_SIZE) &&
534 info->oem_revision == table->oem_revision)
535 return true;
536
537 info++;
538 }
539
540 return false;
541}
542
543static const struct arch_timer_erratum_workaround *
544arch_timer_iterate_errata(enum arch_timer_erratum_match_type type,
545 ate_match_fn_t match_fn,
546 void *arg)
547{
548 int i;
549
550 for (i = 0; i < ARRAY_SIZE(ool_workarounds); i++) {
551 if (ool_workarounds[i].match_type != type)
552 continue;
553
554 if (match_fn(&ool_workarounds[i], arg))
555 return &ool_workarounds[i];
556 }
557
558 return NULL;
559}
560
561static
562void arch_timer_enable_workaround(const struct arch_timer_erratum_workaround *wa,
563 bool local)
564{
565 int i;
566
567 if (local) {
568 __this_cpu_write(timer_unstable_counter_workaround, wa);
569 } else {
570 for_each_possible_cpu(i)
571 per_cpu(timer_unstable_counter_workaround, i) = wa;
572 }
573
574 if (wa->read_cntvct_el0 || wa->read_cntpct_el0)
575 atomic_set(&timer_unstable_counter_workaround_in_use, 1);
576
577 /*
578 * Don't use the vdso fastpath if errata require using the
579 * out-of-line counter accessor. We may change our mind pretty
580 * late in the game (with a per-CPU erratum, for example), so
581 * change both the default value and the vdso itself.
582 */
583 if (wa->read_cntvct_el0) {
584 clocksource_counter.vdso_clock_mode = VDSO_CLOCKMODE_NONE;
585 vdso_default = VDSO_CLOCKMODE_NONE;
586 } else if (wa->disable_compat_vdso && vdso_default != VDSO_CLOCKMODE_NONE) {
587 vdso_default = VDSO_CLOCKMODE_ARCHTIMER_NOCOMPAT;
588 clocksource_counter.vdso_clock_mode = vdso_default;
589 }
590}
591
592static void arch_timer_check_ool_workaround(enum arch_timer_erratum_match_type type,
593 void *arg)
594{
595 const struct arch_timer_erratum_workaround *wa, *__wa;
596 ate_match_fn_t match_fn = NULL;
597 bool local = false;
598
599 switch (type) {
600 case ate_match_dt:
601 match_fn = arch_timer_check_dt_erratum;
602 break;
603 case ate_match_local_cap_id:
604 match_fn = arch_timer_check_local_cap_erratum;
605 local = true;
606 break;
607 case ate_match_acpi_oem_info:
608 match_fn = arch_timer_check_acpi_oem_erratum;
609 break;
610 default:
611 WARN_ON(1);
612 return;
613 }
614
615 wa = arch_timer_iterate_errata(type, match_fn, arg);
616 if (!wa)
617 return;
618
619 __wa = __this_cpu_read(timer_unstable_counter_workaround);
620 if (__wa && wa != __wa)
621 pr_warn("Can't enable workaround for %s (clashes with %s\n)",
622 wa->desc, __wa->desc);
623
624 if (__wa)
625 return;
626
627 arch_timer_enable_workaround(wa, local);
628 pr_info("Enabling %s workaround for %s\n",
629 local ? "local" : "global", wa->desc);
630}
631
632static bool arch_timer_this_cpu_has_cntvct_wa(void)
633{
634 return has_erratum_handler(read_cntvct_el0);
635}
636
637static bool arch_timer_counter_has_wa(void)
638{
639 return atomic_read(&timer_unstable_counter_workaround_in_use);
640}
641#else
642#define arch_timer_check_ool_workaround(t,a) do { } while(0)
643#define arch_timer_this_cpu_has_cntvct_wa() ({false;})
644#define arch_timer_counter_has_wa() ({false;})
645#endif /* CONFIG_ARM_ARCH_TIMER_OOL_WORKAROUND */
646
647static __always_inline irqreturn_t timer_handler(const int access,
648 struct clock_event_device *evt)
649{
650 unsigned long ctrl;
651
652 ctrl = arch_timer_reg_read(access, ARCH_TIMER_REG_CTRL, evt);
653 if (ctrl & ARCH_TIMER_CTRL_IT_STAT) {
654 ctrl |= ARCH_TIMER_CTRL_IT_MASK;
655 arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl, evt);
656 evt->event_handler(evt);
657 return IRQ_HANDLED;
658 }
659
660 return IRQ_NONE;
661}
662
663static irqreturn_t arch_timer_handler_virt(int irq, void *dev_id)
664{
665 struct clock_event_device *evt = dev_id;
666
667 return timer_handler(ARCH_TIMER_VIRT_ACCESS, evt);
668}
669
670static irqreturn_t arch_timer_handler_phys(int irq, void *dev_id)
671{
672 struct clock_event_device *evt = dev_id;
673
674 return timer_handler(ARCH_TIMER_PHYS_ACCESS, evt);
675}
676
677static irqreturn_t arch_timer_handler_phys_mem(int irq, void *dev_id)
678{
679 struct clock_event_device *evt = dev_id;
680
681 return timer_handler(ARCH_TIMER_MEM_PHYS_ACCESS, evt);
682}
683
684static irqreturn_t arch_timer_handler_virt_mem(int irq, void *dev_id)
685{
686 struct clock_event_device *evt = dev_id;
687
688 return timer_handler(ARCH_TIMER_MEM_VIRT_ACCESS, evt);
689}
690
691static __always_inline int arch_timer_shutdown(const int access,
692 struct clock_event_device *clk)
693{
694 unsigned long ctrl;
695
696 ctrl = arch_timer_reg_read(access, ARCH_TIMER_REG_CTRL, clk);
697 ctrl &= ~ARCH_TIMER_CTRL_ENABLE;
698 arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl, clk);
699
700 return 0;
701}
702
703static int arch_timer_shutdown_virt(struct clock_event_device *clk)
704{
705 return arch_timer_shutdown(ARCH_TIMER_VIRT_ACCESS, clk);
706}
707
708static int arch_timer_shutdown_phys(struct clock_event_device *clk)
709{
710 return arch_timer_shutdown(ARCH_TIMER_PHYS_ACCESS, clk);
711}
712
713static int arch_timer_shutdown_virt_mem(struct clock_event_device *clk)
714{
715 return arch_timer_shutdown(ARCH_TIMER_MEM_VIRT_ACCESS, clk);
716}
717
718static int arch_timer_shutdown_phys_mem(struct clock_event_device *clk)
719{
720 return arch_timer_shutdown(ARCH_TIMER_MEM_PHYS_ACCESS, clk);
721}
722
723static __always_inline void set_next_event(const int access, unsigned long evt,
724 struct clock_event_device *clk)
725{
726 unsigned long ctrl;
727 u64 cnt;
728
729 ctrl = arch_timer_reg_read(access, ARCH_TIMER_REG_CTRL, clk);
730 ctrl |= ARCH_TIMER_CTRL_ENABLE;
731 ctrl &= ~ARCH_TIMER_CTRL_IT_MASK;
732
733 if (access == ARCH_TIMER_PHYS_ACCESS)
734 cnt = __arch_counter_get_cntpct();
735 else
736 cnt = __arch_counter_get_cntvct();
737
738 arch_timer_reg_write(access, ARCH_TIMER_REG_CVAL, evt + cnt, clk);
739 arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl, clk);
740}
741
742static int arch_timer_set_next_event_virt(unsigned long evt,
743 struct clock_event_device *clk)
744{
745 set_next_event(ARCH_TIMER_VIRT_ACCESS, evt, clk);
746 return 0;
747}
748
749static int arch_timer_set_next_event_phys(unsigned long evt,
750 struct clock_event_device *clk)
751{
752 set_next_event(ARCH_TIMER_PHYS_ACCESS, evt, clk);
753 return 0;
754}
755
756static u64 arch_counter_get_cnt_mem(struct arch_timer *t, int offset_lo)
757{
758 u32 cnt_lo, cnt_hi, tmp_hi;
759
760 do {
761 cnt_hi = readl_relaxed(t->base + offset_lo + 4);
762 cnt_lo = readl_relaxed(t->base + offset_lo);
763 tmp_hi = readl_relaxed(t->base + offset_lo + 4);
764 } while (cnt_hi != tmp_hi);
765
766 return ((u64) cnt_hi << 32) | cnt_lo;
767}
768
769static __always_inline void set_next_event_mem(const int access, unsigned long evt,
770 struct clock_event_device *clk)
771{
772 struct arch_timer *timer = to_arch_timer(clk);
773 unsigned long ctrl;
774 u64 cnt;
775
776 ctrl = arch_timer_reg_read(access, ARCH_TIMER_REG_CTRL, clk);
777 ctrl |= ARCH_TIMER_CTRL_ENABLE;
778 ctrl &= ~ARCH_TIMER_CTRL_IT_MASK;
779
780 if (access == ARCH_TIMER_MEM_VIRT_ACCESS)
781 cnt = arch_counter_get_cnt_mem(timer, CNTVCT_LO);
782 else
783 cnt = arch_counter_get_cnt_mem(timer, CNTPCT_LO);
784
785 arch_timer_reg_write(access, ARCH_TIMER_REG_CVAL, evt + cnt, clk);
786 arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl, clk);
787}
788
789static int arch_timer_set_next_event_virt_mem(unsigned long evt,
790 struct clock_event_device *clk)
791{
792 set_next_event_mem(ARCH_TIMER_MEM_VIRT_ACCESS, evt, clk);
793 return 0;
794}
795
796static int arch_timer_set_next_event_phys_mem(unsigned long evt,
797 struct clock_event_device *clk)
798{
799 set_next_event_mem(ARCH_TIMER_MEM_PHYS_ACCESS, evt, clk);
800 return 0;
801}
802
803static u64 __arch_timer_check_delta(void)
804{
805#ifdef CONFIG_ARM64
806 const struct midr_range broken_cval_midrs[] = {
807 /*
808 * XGene-1 implements CVAL in terms of TVAL, meaning
809 * that the maximum timer range is 32bit. Shame on them.
810 *
811 * Note that TVAL is signed, thus has only 31 of its
812 * 32 bits to express magnitude.
813 */
814 MIDR_ALL_VERSIONS(MIDR_CPU_MODEL(ARM_CPU_IMP_APM,
815 APM_CPU_PART_POTENZA)),
816 {},
817 };
818
819 if (is_midr_in_range_list(read_cpuid_id(), broken_cval_midrs)) {
820 pr_warn_once("Broken CNTx_CVAL_EL1, using 31 bit TVAL instead.\n");
821 return CLOCKSOURCE_MASK(31);
822 }
823#endif
824 return CLOCKSOURCE_MASK(arch_counter_get_width());
825}
826
827static void __arch_timer_setup(unsigned type,
828 struct clock_event_device *clk)
829{
830 u64 max_delta;
831
832 clk->features = CLOCK_EVT_FEAT_ONESHOT;
833
834 if (type == ARCH_TIMER_TYPE_CP15) {
835 typeof(clk->set_next_event) sne;
836
837 arch_timer_check_ool_workaround(ate_match_local_cap_id, NULL);
838
839 if (arch_timer_c3stop)
840 clk->features |= CLOCK_EVT_FEAT_C3STOP;
841 clk->name = "arch_sys_timer";
842 clk->rating = 450;
843 clk->cpumask = cpumask_of(smp_processor_id());
844 clk->irq = arch_timer_ppi[arch_timer_uses_ppi];
845 switch (arch_timer_uses_ppi) {
846 case ARCH_TIMER_VIRT_PPI:
847 clk->set_state_shutdown = arch_timer_shutdown_virt;
848 clk->set_state_oneshot_stopped = arch_timer_shutdown_virt;
849 sne = erratum_handler(set_next_event_virt);
850 break;
851 case ARCH_TIMER_PHYS_SECURE_PPI:
852 case ARCH_TIMER_PHYS_NONSECURE_PPI:
853 case ARCH_TIMER_HYP_PPI:
854 clk->set_state_shutdown = arch_timer_shutdown_phys;
855 clk->set_state_oneshot_stopped = arch_timer_shutdown_phys;
856 sne = erratum_handler(set_next_event_phys);
857 break;
858 default:
859 BUG();
860 }
861
862 clk->set_next_event = sne;
863 max_delta = __arch_timer_check_delta();
864 } else {
865 clk->features |= CLOCK_EVT_FEAT_DYNIRQ;
866 clk->name = "arch_mem_timer";
867 clk->rating = 400;
868 clk->cpumask = cpu_possible_mask;
869 if (arch_timer_mem_use_virtual) {
870 clk->set_state_shutdown = arch_timer_shutdown_virt_mem;
871 clk->set_state_oneshot_stopped = arch_timer_shutdown_virt_mem;
872 clk->set_next_event =
873 arch_timer_set_next_event_virt_mem;
874 } else {
875 clk->set_state_shutdown = arch_timer_shutdown_phys_mem;
876 clk->set_state_oneshot_stopped = arch_timer_shutdown_phys_mem;
877 clk->set_next_event =
878 arch_timer_set_next_event_phys_mem;
879 }
880
881 max_delta = CLOCKSOURCE_MASK(56);
882 }
883
884 clk->set_state_shutdown(clk);
885
886 clockevents_config_and_register(clk, arch_timer_rate, 0xf, max_delta);
887}
888
889static void arch_timer_evtstrm_enable(unsigned int divider)
890{
891 u32 cntkctl = arch_timer_get_cntkctl();
892
893#ifdef CONFIG_ARM64
894 /* ECV is likely to require a large divider. Use the EVNTIS flag. */
895 if (cpus_have_const_cap(ARM64_HAS_ECV) && divider > 15) {
896 cntkctl |= ARCH_TIMER_EVT_INTERVAL_SCALE;
897 divider -= 8;
898 }
899#endif
900
901 divider = min(divider, 15U);
902 cntkctl &= ~ARCH_TIMER_EVT_TRIGGER_MASK;
903 /* Set the divider and enable virtual event stream */
904 cntkctl |= (divider << ARCH_TIMER_EVT_TRIGGER_SHIFT)
905 | ARCH_TIMER_VIRT_EVT_EN;
906 arch_timer_set_cntkctl(cntkctl);
907 arch_timer_set_evtstrm_feature();
908 cpumask_set_cpu(smp_processor_id(), &evtstrm_available);
909}
910
911static void arch_timer_configure_evtstream(void)
912{
913 int evt_stream_div, lsb;
914
915 /*
916 * As the event stream can at most be generated at half the frequency
917 * of the counter, use half the frequency when computing the divider.
918 */
919 evt_stream_div = arch_timer_rate / ARCH_TIMER_EVT_STREAM_FREQ / 2;
920
921 /*
922 * Find the closest power of two to the divisor. If the adjacent bit
923 * of lsb (last set bit, starts from 0) is set, then we use (lsb + 1).
924 */
925 lsb = fls(evt_stream_div) - 1;
926 if (lsb > 0 && (evt_stream_div & BIT(lsb - 1)))
927 lsb++;
928
929 /* enable event stream */
930 arch_timer_evtstrm_enable(max(0, lsb));
931}
932
933static void arch_counter_set_user_access(void)
934{
935 u32 cntkctl = arch_timer_get_cntkctl();
936
937 /* Disable user access to the timers and both counters */
938 /* Also disable virtual event stream */
939 cntkctl &= ~(ARCH_TIMER_USR_PT_ACCESS_EN
940 | ARCH_TIMER_USR_VT_ACCESS_EN
941 | ARCH_TIMER_USR_VCT_ACCESS_EN
942 | ARCH_TIMER_VIRT_EVT_EN
943 | ARCH_TIMER_USR_PCT_ACCESS_EN);
944
945 /*
946 * Enable user access to the virtual counter if it doesn't
947 * need to be workaround. The vdso may have been already
948 * disabled though.
949 */
950 if (arch_timer_this_cpu_has_cntvct_wa())
951 pr_info("CPU%d: Trapping CNTVCT access\n", smp_processor_id());
952 else
953 cntkctl |= ARCH_TIMER_USR_VCT_ACCESS_EN;
954
955 arch_timer_set_cntkctl(cntkctl);
956}
957
958static bool arch_timer_has_nonsecure_ppi(void)
959{
960 return (arch_timer_uses_ppi == ARCH_TIMER_PHYS_SECURE_PPI &&
961 arch_timer_ppi[ARCH_TIMER_PHYS_NONSECURE_PPI]);
962}
963
964static u32 check_ppi_trigger(int irq)
965{
966 u32 flags = irq_get_trigger_type(irq);
967
968 if (flags != IRQF_TRIGGER_HIGH && flags != IRQF_TRIGGER_LOW) {
969 pr_warn("WARNING: Invalid trigger for IRQ%d, assuming level low\n", irq);
970 pr_warn("WARNING: Please fix your firmware\n");
971 flags = IRQF_TRIGGER_LOW;
972 }
973
974 return flags;
975}
976
977static int arch_timer_starting_cpu(unsigned int cpu)
978{
979 struct clock_event_device *clk = this_cpu_ptr(arch_timer_evt);
980 u32 flags;
981
982 __arch_timer_setup(ARCH_TIMER_TYPE_CP15, clk);
983
984 flags = check_ppi_trigger(arch_timer_ppi[arch_timer_uses_ppi]);
985 enable_percpu_irq(arch_timer_ppi[arch_timer_uses_ppi], flags);
986
987 if (arch_timer_has_nonsecure_ppi()) {
988 flags = check_ppi_trigger(arch_timer_ppi[ARCH_TIMER_PHYS_NONSECURE_PPI]);
989 enable_percpu_irq(arch_timer_ppi[ARCH_TIMER_PHYS_NONSECURE_PPI],
990 flags);
991 }
992
993 arch_counter_set_user_access();
994 if (evtstrm_enable)
995 arch_timer_configure_evtstream();
996
997 return 0;
998}
999
1000static int validate_timer_rate(void)
1001{
1002 if (!arch_timer_rate)
1003 return -EINVAL;
1004
1005 /* Arch timer frequency < 1MHz can cause trouble */
1006 WARN_ON(arch_timer_rate < 1000000);
1007
1008 return 0;
1009}
1010
1011/*
1012 * For historical reasons, when probing with DT we use whichever (non-zero)
1013 * rate was probed first, and don't verify that others match. If the first node
1014 * probed has a clock-frequency property, this overrides the HW register.
1015 */
1016static void __init arch_timer_of_configure_rate(u32 rate, struct device_node *np)
1017{
1018 /* Who has more than one independent system counter? */
1019 if (arch_timer_rate)
1020 return;
1021
1022 if (of_property_read_u32(np, "clock-frequency", &arch_timer_rate))
1023 arch_timer_rate = rate;
1024
1025 /* Check the timer frequency. */
1026 if (validate_timer_rate())
1027 pr_warn("frequency not available\n");
1028}
1029
1030static void __init arch_timer_banner(unsigned type)
1031{
1032 pr_info("%s%s%s timer(s) running at %lu.%02luMHz (%s%s%s).\n",
1033 type & ARCH_TIMER_TYPE_CP15 ? "cp15" : "",
1034 type == (ARCH_TIMER_TYPE_CP15 | ARCH_TIMER_TYPE_MEM) ?
1035 " and " : "",
1036 type & ARCH_TIMER_TYPE_MEM ? "mmio" : "",
1037 (unsigned long)arch_timer_rate / 1000000,
1038 (unsigned long)(arch_timer_rate / 10000) % 100,
1039 type & ARCH_TIMER_TYPE_CP15 ?
1040 (arch_timer_uses_ppi == ARCH_TIMER_VIRT_PPI) ? "virt" : "phys" :
1041 "",
1042 type == (ARCH_TIMER_TYPE_CP15 | ARCH_TIMER_TYPE_MEM) ? "/" : "",
1043 type & ARCH_TIMER_TYPE_MEM ?
1044 arch_timer_mem_use_virtual ? "virt" : "phys" :
1045 "");
1046}
1047
1048u32 arch_timer_get_rate(void)
1049{
1050 return arch_timer_rate;
1051}
1052
1053bool arch_timer_evtstrm_available(void)
1054{
1055 /*
1056 * We might get called from a preemptible context. This is fine
1057 * because availability of the event stream should be always the same
1058 * for a preemptible context and context where we might resume a task.
1059 */
1060 return cpumask_test_cpu(raw_smp_processor_id(), &evtstrm_available);
1061}
1062
1063static u64 arch_counter_get_cntvct_mem(void)
1064{
1065 return arch_counter_get_cnt_mem(arch_timer_mem, CNTVCT_LO);
1066}
1067
1068static struct arch_timer_kvm_info arch_timer_kvm_info;
1069
1070struct arch_timer_kvm_info *arch_timer_get_kvm_info(void)
1071{
1072 return &arch_timer_kvm_info;
1073}
1074
1075static void __init arch_counter_register(unsigned type)
1076{
1077 u64 start_count;
1078 int width;
1079
1080 /* Register the CP15 based counter if we have one */
1081 if (type & ARCH_TIMER_TYPE_CP15) {
1082 u64 (*rd)(void);
1083
1084 if ((IS_ENABLED(CONFIG_ARM64) && !is_hyp_mode_available()) ||
1085 arch_timer_uses_ppi == ARCH_TIMER_VIRT_PPI) {
1086 if (arch_timer_counter_has_wa())
1087 rd = arch_counter_get_cntvct_stable;
1088 else
1089 rd = arch_counter_get_cntvct;
1090 } else {
1091 if (arch_timer_counter_has_wa())
1092 rd = arch_counter_get_cntpct_stable;
1093 else
1094 rd = arch_counter_get_cntpct;
1095 }
1096
1097 arch_timer_read_counter = rd;
1098 clocksource_counter.vdso_clock_mode = vdso_default;
1099 } else {
1100 arch_timer_read_counter = arch_counter_get_cntvct_mem;
1101 }
1102
1103 width = arch_counter_get_width();
1104 clocksource_counter.mask = CLOCKSOURCE_MASK(width);
1105 cyclecounter.mask = CLOCKSOURCE_MASK(width);
1106
1107 if (!arch_counter_suspend_stop)
1108 clocksource_counter.flags |= CLOCK_SOURCE_SUSPEND_NONSTOP;
1109 start_count = arch_timer_read_counter();
1110 clocksource_register_hz(&clocksource_counter, arch_timer_rate);
1111 cyclecounter.mult = clocksource_counter.mult;
1112 cyclecounter.shift = clocksource_counter.shift;
1113 timecounter_init(&arch_timer_kvm_info.timecounter,
1114 &cyclecounter, start_count);
1115
1116 sched_clock_register(arch_timer_read_counter, width, arch_timer_rate);
1117}
1118
1119static void arch_timer_stop(struct clock_event_device *clk)
1120{
1121 pr_debug("disable IRQ%d cpu #%d\n", clk->irq, smp_processor_id());
1122
1123 disable_percpu_irq(arch_timer_ppi[arch_timer_uses_ppi]);
1124 if (arch_timer_has_nonsecure_ppi())
1125 disable_percpu_irq(arch_timer_ppi[ARCH_TIMER_PHYS_NONSECURE_PPI]);
1126
1127 clk->set_state_shutdown(clk);
1128}
1129
1130static int arch_timer_dying_cpu(unsigned int cpu)
1131{
1132 struct clock_event_device *clk = this_cpu_ptr(arch_timer_evt);
1133
1134 cpumask_clear_cpu(smp_processor_id(), &evtstrm_available);
1135
1136 arch_timer_stop(clk);
1137 return 0;
1138}
1139
1140#ifdef CONFIG_CPU_PM
1141static DEFINE_PER_CPU(unsigned long, saved_cntkctl);
1142static int arch_timer_cpu_pm_notify(struct notifier_block *self,
1143 unsigned long action, void *hcpu)
1144{
1145 if (action == CPU_PM_ENTER) {
1146 __this_cpu_write(saved_cntkctl, arch_timer_get_cntkctl());
1147
1148 cpumask_clear_cpu(smp_processor_id(), &evtstrm_available);
1149 } else if (action == CPU_PM_ENTER_FAILED || action == CPU_PM_EXIT) {
1150 arch_timer_set_cntkctl(__this_cpu_read(saved_cntkctl));
1151
1152 if (arch_timer_have_evtstrm_feature())
1153 cpumask_set_cpu(smp_processor_id(), &evtstrm_available);
1154 }
1155 return NOTIFY_OK;
1156}
1157
1158static struct notifier_block arch_timer_cpu_pm_notifier = {
1159 .notifier_call = arch_timer_cpu_pm_notify,
1160};
1161
1162static int __init arch_timer_cpu_pm_init(void)
1163{
1164 return cpu_pm_register_notifier(&arch_timer_cpu_pm_notifier);
1165}
1166
1167static void __init arch_timer_cpu_pm_deinit(void)
1168{
1169 WARN_ON(cpu_pm_unregister_notifier(&arch_timer_cpu_pm_notifier));
1170}
1171
1172#else
1173static int __init arch_timer_cpu_pm_init(void)
1174{
1175 return 0;
1176}
1177
1178static void __init arch_timer_cpu_pm_deinit(void)
1179{
1180}
1181#endif
1182
1183static int __init arch_timer_register(void)
1184{
1185 int err;
1186 int ppi;
1187
1188 arch_timer_evt = alloc_percpu(struct clock_event_device);
1189 if (!arch_timer_evt) {
1190 err = -ENOMEM;
1191 goto out;
1192 }
1193
1194 ppi = arch_timer_ppi[arch_timer_uses_ppi];
1195 switch (arch_timer_uses_ppi) {
1196 case ARCH_TIMER_VIRT_PPI:
1197 err = request_percpu_irq(ppi, arch_timer_handler_virt,
1198 "arch_timer", arch_timer_evt);
1199 break;
1200 case ARCH_TIMER_PHYS_SECURE_PPI:
1201 case ARCH_TIMER_PHYS_NONSECURE_PPI:
1202 err = request_percpu_irq(ppi, arch_timer_handler_phys,
1203 "arch_timer", arch_timer_evt);
1204 if (!err && arch_timer_has_nonsecure_ppi()) {
1205 ppi = arch_timer_ppi[ARCH_TIMER_PHYS_NONSECURE_PPI];
1206 err = request_percpu_irq(ppi, arch_timer_handler_phys,
1207 "arch_timer", arch_timer_evt);
1208 if (err)
1209 free_percpu_irq(arch_timer_ppi[ARCH_TIMER_PHYS_SECURE_PPI],
1210 arch_timer_evt);
1211 }
1212 break;
1213 case ARCH_TIMER_HYP_PPI:
1214 err = request_percpu_irq(ppi, arch_timer_handler_phys,
1215 "arch_timer", arch_timer_evt);
1216 break;
1217 default:
1218 BUG();
1219 }
1220
1221 if (err) {
1222 pr_err("can't register interrupt %d (%d)\n", ppi, err);
1223 goto out_free;
1224 }
1225
1226 err = arch_timer_cpu_pm_init();
1227 if (err)
1228 goto out_unreg_notify;
1229
1230 /* Register and immediately configure the timer on the boot CPU */
1231 err = cpuhp_setup_state(CPUHP_AP_ARM_ARCH_TIMER_STARTING,
1232 "clockevents/arm/arch_timer:starting",
1233 arch_timer_starting_cpu, arch_timer_dying_cpu);
1234 if (err)
1235 goto out_unreg_cpupm;
1236 return 0;
1237
1238out_unreg_cpupm:
1239 arch_timer_cpu_pm_deinit();
1240
1241out_unreg_notify:
1242 free_percpu_irq(arch_timer_ppi[arch_timer_uses_ppi], arch_timer_evt);
1243 if (arch_timer_has_nonsecure_ppi())
1244 free_percpu_irq(arch_timer_ppi[ARCH_TIMER_PHYS_NONSECURE_PPI],
1245 arch_timer_evt);
1246
1247out_free:
1248 free_percpu(arch_timer_evt);
1249out:
1250 return err;
1251}
1252
1253static int __init arch_timer_mem_register(void __iomem *base, unsigned int irq)
1254{
1255 int ret;
1256 irq_handler_t func;
1257
1258 arch_timer_mem = kzalloc(sizeof(*arch_timer_mem), GFP_KERNEL);
1259 if (!arch_timer_mem)
1260 return -ENOMEM;
1261
1262 arch_timer_mem->base = base;
1263 arch_timer_mem->evt.irq = irq;
1264 __arch_timer_setup(ARCH_TIMER_TYPE_MEM, &arch_timer_mem->evt);
1265
1266 if (arch_timer_mem_use_virtual)
1267 func = arch_timer_handler_virt_mem;
1268 else
1269 func = arch_timer_handler_phys_mem;
1270
1271 ret = request_irq(irq, func, IRQF_TIMER, "arch_mem_timer", &arch_timer_mem->evt);
1272 if (ret) {
1273 pr_err("Failed to request mem timer irq\n");
1274 kfree(arch_timer_mem);
1275 arch_timer_mem = NULL;
1276 }
1277
1278 return ret;
1279}
1280
1281static const struct of_device_id arch_timer_of_match[] __initconst = {
1282 { .compatible = "arm,armv7-timer", },
1283 { .compatible = "arm,armv8-timer", },
1284 {},
1285};
1286
1287static const struct of_device_id arch_timer_mem_of_match[] __initconst = {
1288 { .compatible = "arm,armv7-timer-mem", },
1289 {},
1290};
1291
1292static bool __init arch_timer_needs_of_probing(void)
1293{
1294 struct device_node *dn;
1295 bool needs_probing = false;
1296 unsigned int mask = ARCH_TIMER_TYPE_CP15 | ARCH_TIMER_TYPE_MEM;
1297
1298 /* We have two timers, and both device-tree nodes are probed. */
1299 if ((arch_timers_present & mask) == mask)
1300 return false;
1301
1302 /*
1303 * Only one type of timer is probed,
1304 * check if we have another type of timer node in device-tree.
1305 */
1306 if (arch_timers_present & ARCH_TIMER_TYPE_CP15)
1307 dn = of_find_matching_node(NULL, arch_timer_mem_of_match);
1308 else
1309 dn = of_find_matching_node(NULL, arch_timer_of_match);
1310
1311 if (dn && of_device_is_available(dn))
1312 needs_probing = true;
1313
1314 of_node_put(dn);
1315
1316 return needs_probing;
1317}
1318
1319static int __init arch_timer_common_init(void)
1320{
1321 arch_timer_banner(arch_timers_present);
1322 arch_counter_register(arch_timers_present);
1323 return arch_timer_arch_init();
1324}
1325
1326/**
1327 * arch_timer_select_ppi() - Select suitable PPI for the current system.
1328 *
1329 * If HYP mode is available, we know that the physical timer
1330 * has been configured to be accessible from PL1. Use it, so
1331 * that a guest can use the virtual timer instead.
1332 *
1333 * On ARMv8.1 with VH extensions, the kernel runs in HYP. VHE
1334 * accesses to CNTP_*_EL1 registers are silently redirected to
1335 * their CNTHP_*_EL2 counterparts, and use a different PPI
1336 * number.
1337 *
1338 * If no interrupt provided for virtual timer, we'll have to
1339 * stick to the physical timer. It'd better be accessible...
1340 * For arm64 we never use the secure interrupt.
1341 *
1342 * Return: a suitable PPI type for the current system.
1343 */
1344static enum arch_timer_ppi_nr __init arch_timer_select_ppi(void)
1345{
1346 if (is_kernel_in_hyp_mode())
1347 return ARCH_TIMER_HYP_PPI;
1348
1349 if (!is_hyp_mode_available() && arch_timer_ppi[ARCH_TIMER_VIRT_PPI])
1350 return ARCH_TIMER_VIRT_PPI;
1351
1352 if (IS_ENABLED(CONFIG_ARM64))
1353 return ARCH_TIMER_PHYS_NONSECURE_PPI;
1354
1355 return ARCH_TIMER_PHYS_SECURE_PPI;
1356}
1357
1358static void __init arch_timer_populate_kvm_info(void)
1359{
1360 arch_timer_kvm_info.virtual_irq = arch_timer_ppi[ARCH_TIMER_VIRT_PPI];
1361 if (is_kernel_in_hyp_mode())
1362 arch_timer_kvm_info.physical_irq = arch_timer_ppi[ARCH_TIMER_PHYS_NONSECURE_PPI];
1363}
1364
1365static int __init arch_timer_of_init(struct device_node *np)
1366{
1367 int i, irq, ret;
1368 u32 rate;
1369 bool has_names;
1370
1371 if (arch_timers_present & ARCH_TIMER_TYPE_CP15) {
1372 pr_warn("multiple nodes in dt, skipping\n");
1373 return 0;
1374 }
1375
1376 arch_timers_present |= ARCH_TIMER_TYPE_CP15;
1377
1378 has_names = of_property_read_bool(np, "interrupt-names");
1379
1380 for (i = ARCH_TIMER_PHYS_SECURE_PPI; i < ARCH_TIMER_MAX_TIMER_PPI; i++) {
1381 if (has_names)
1382 irq = of_irq_get_byname(np, arch_timer_ppi_names[i]);
1383 else
1384 irq = of_irq_get(np, i);
1385 if (irq > 0)
1386 arch_timer_ppi[i] = irq;
1387 }
1388
1389 arch_timer_populate_kvm_info();
1390
1391 rate = arch_timer_get_cntfrq();
1392 arch_timer_of_configure_rate(rate, np);
1393
1394 arch_timer_c3stop = !of_property_read_bool(np, "always-on");
1395
1396 /* Check for globally applicable workarounds */
1397 arch_timer_check_ool_workaround(ate_match_dt, np);
1398
1399 /*
1400 * If we cannot rely on firmware initializing the timer registers then
1401 * we should use the physical timers instead.
1402 */
1403 if (IS_ENABLED(CONFIG_ARM) &&
1404 of_property_read_bool(np, "arm,cpu-registers-not-fw-configured"))
1405 arch_timer_uses_ppi = ARCH_TIMER_PHYS_SECURE_PPI;
1406 else
1407 arch_timer_uses_ppi = arch_timer_select_ppi();
1408
1409 if (!arch_timer_ppi[arch_timer_uses_ppi]) {
1410 pr_err("No interrupt available, giving up\n");
1411 return -EINVAL;
1412 }
1413
1414 /* On some systems, the counter stops ticking when in suspend. */
1415 arch_counter_suspend_stop = of_property_read_bool(np,
1416 "arm,no-tick-in-suspend");
1417
1418 ret = arch_timer_register();
1419 if (ret)
1420 return ret;
1421
1422 if (arch_timer_needs_of_probing())
1423 return 0;
1424
1425 return arch_timer_common_init();
1426}
1427TIMER_OF_DECLARE(armv7_arch_timer, "arm,armv7-timer", arch_timer_of_init);
1428TIMER_OF_DECLARE(armv8_arch_timer, "arm,armv8-timer", arch_timer_of_init);
1429
1430static u32 __init
1431arch_timer_mem_frame_get_cntfrq(struct arch_timer_mem_frame *frame)
1432{
1433 void __iomem *base;
1434 u32 rate;
1435
1436 base = ioremap(frame->cntbase, frame->size);
1437 if (!base) {
1438 pr_err("Unable to map frame @ %pa\n", &frame->cntbase);
1439 return 0;
1440 }
1441
1442 rate = readl_relaxed(base + CNTFRQ);
1443
1444 iounmap(base);
1445
1446 return rate;
1447}
1448
1449static struct arch_timer_mem_frame * __init
1450arch_timer_mem_find_best_frame(struct arch_timer_mem *timer_mem)
1451{
1452 struct arch_timer_mem_frame *frame, *best_frame = NULL;
1453 void __iomem *cntctlbase;
1454 u32 cnttidr;
1455 int i;
1456
1457 cntctlbase = ioremap(timer_mem->cntctlbase, timer_mem->size);
1458 if (!cntctlbase) {
1459 pr_err("Can't map CNTCTLBase @ %pa\n",
1460 &timer_mem->cntctlbase);
1461 return NULL;
1462 }
1463
1464 cnttidr = readl_relaxed(cntctlbase + CNTTIDR);
1465
1466 /*
1467 * Try to find a virtual capable frame. Otherwise fall back to a
1468 * physical capable frame.
1469 */
1470 for (i = 0; i < ARCH_TIMER_MEM_MAX_FRAMES; i++) {
1471 u32 cntacr = CNTACR_RFRQ | CNTACR_RWPT | CNTACR_RPCT |
1472 CNTACR_RWVT | CNTACR_RVOFF | CNTACR_RVCT;
1473
1474 frame = &timer_mem->frame[i];
1475 if (!frame->valid)
1476 continue;
1477
1478 /* Try enabling everything, and see what sticks */
1479 writel_relaxed(cntacr, cntctlbase + CNTACR(i));
1480 cntacr = readl_relaxed(cntctlbase + CNTACR(i));
1481
1482 if ((cnttidr & CNTTIDR_VIRT(i)) &&
1483 !(~cntacr & (CNTACR_RWVT | CNTACR_RVCT))) {
1484 best_frame = frame;
1485 arch_timer_mem_use_virtual = true;
1486 break;
1487 }
1488
1489 if (~cntacr & (CNTACR_RWPT | CNTACR_RPCT))
1490 continue;
1491
1492 best_frame = frame;
1493 }
1494
1495 iounmap(cntctlbase);
1496
1497 return best_frame;
1498}
1499
1500static int __init
1501arch_timer_mem_frame_register(struct arch_timer_mem_frame *frame)
1502{
1503 void __iomem *base;
1504 int ret, irq = 0;
1505
1506 if (arch_timer_mem_use_virtual)
1507 irq = frame->virt_irq;
1508 else
1509 irq = frame->phys_irq;
1510
1511 if (!irq) {
1512 pr_err("Frame missing %s irq.\n",
1513 arch_timer_mem_use_virtual ? "virt" : "phys");
1514 return -EINVAL;
1515 }
1516
1517 if (!request_mem_region(frame->cntbase, frame->size,
1518 "arch_mem_timer"))
1519 return -EBUSY;
1520
1521 base = ioremap(frame->cntbase, frame->size);
1522 if (!base) {
1523 pr_err("Can't map frame's registers\n");
1524 return -ENXIO;
1525 }
1526
1527 ret = arch_timer_mem_register(base, irq);
1528 if (ret) {
1529 iounmap(base);
1530 return ret;
1531 }
1532
1533 arch_timers_present |= ARCH_TIMER_TYPE_MEM;
1534
1535 return 0;
1536}
1537
1538static int __init arch_timer_mem_of_init(struct device_node *np)
1539{
1540 struct arch_timer_mem *timer_mem;
1541 struct arch_timer_mem_frame *frame;
1542 struct device_node *frame_node;
1543 struct resource res;
1544 int ret = -EINVAL;
1545 u32 rate;
1546
1547 timer_mem = kzalloc(sizeof(*timer_mem), GFP_KERNEL);
1548 if (!timer_mem)
1549 return -ENOMEM;
1550
1551 if (of_address_to_resource(np, 0, &res))
1552 goto out;
1553 timer_mem->cntctlbase = res.start;
1554 timer_mem->size = resource_size(&res);
1555
1556 for_each_available_child_of_node(np, frame_node) {
1557 u32 n;
1558 struct arch_timer_mem_frame *frame;
1559
1560 if (of_property_read_u32(frame_node, "frame-number", &n)) {
1561 pr_err(FW_BUG "Missing frame-number.\n");
1562 of_node_put(frame_node);
1563 goto out;
1564 }
1565 if (n >= ARCH_TIMER_MEM_MAX_FRAMES) {
1566 pr_err(FW_BUG "Wrong frame-number, only 0-%u are permitted.\n",
1567 ARCH_TIMER_MEM_MAX_FRAMES - 1);
1568 of_node_put(frame_node);
1569 goto out;
1570 }
1571 frame = &timer_mem->frame[n];
1572
1573 if (frame->valid) {
1574 pr_err(FW_BUG "Duplicated frame-number.\n");
1575 of_node_put(frame_node);
1576 goto out;
1577 }
1578
1579 if (of_address_to_resource(frame_node, 0, &res)) {
1580 of_node_put(frame_node);
1581 goto out;
1582 }
1583 frame->cntbase = res.start;
1584 frame->size = resource_size(&res);
1585
1586 frame->virt_irq = irq_of_parse_and_map(frame_node,
1587 ARCH_TIMER_VIRT_SPI);
1588 frame->phys_irq = irq_of_parse_and_map(frame_node,
1589 ARCH_TIMER_PHYS_SPI);
1590
1591 frame->valid = true;
1592 }
1593
1594 frame = arch_timer_mem_find_best_frame(timer_mem);
1595 if (!frame) {
1596 pr_err("Unable to find a suitable frame in timer @ %pa\n",
1597 &timer_mem->cntctlbase);
1598 ret = -EINVAL;
1599 goto out;
1600 }
1601
1602 rate = arch_timer_mem_frame_get_cntfrq(frame);
1603 arch_timer_of_configure_rate(rate, np);
1604
1605 ret = arch_timer_mem_frame_register(frame);
1606 if (!ret && !arch_timer_needs_of_probing())
1607 ret = arch_timer_common_init();
1608out:
1609 kfree(timer_mem);
1610 return ret;
1611}
1612TIMER_OF_DECLARE(armv7_arch_timer_mem, "arm,armv7-timer-mem",
1613 arch_timer_mem_of_init);
1614
1615#ifdef CONFIG_ACPI_GTDT
1616static int __init
1617arch_timer_mem_verify_cntfrq(struct arch_timer_mem *timer_mem)
1618{
1619 struct arch_timer_mem_frame *frame;
1620 u32 rate;
1621 int i;
1622
1623 for (i = 0; i < ARCH_TIMER_MEM_MAX_FRAMES; i++) {
1624 frame = &timer_mem->frame[i];
1625
1626 if (!frame->valid)
1627 continue;
1628
1629 rate = arch_timer_mem_frame_get_cntfrq(frame);
1630 if (rate == arch_timer_rate)
1631 continue;
1632
1633 pr_err(FW_BUG "CNTFRQ mismatch: frame @ %pa: (0x%08lx), CPU: (0x%08lx)\n",
1634 &frame->cntbase,
1635 (unsigned long)rate, (unsigned long)arch_timer_rate);
1636
1637 return -EINVAL;
1638 }
1639
1640 return 0;
1641}
1642
1643static int __init arch_timer_mem_acpi_init(int platform_timer_count)
1644{
1645 struct arch_timer_mem *timers, *timer;
1646 struct arch_timer_mem_frame *frame, *best_frame = NULL;
1647 int timer_count, i, ret = 0;
1648
1649 timers = kcalloc(platform_timer_count, sizeof(*timers),
1650 GFP_KERNEL);
1651 if (!timers)
1652 return -ENOMEM;
1653
1654 ret = acpi_arch_timer_mem_init(timers, &timer_count);
1655 if (ret || !timer_count)
1656 goto out;
1657
1658 /*
1659 * While unlikely, it's theoretically possible that none of the frames
1660 * in a timer expose the combination of feature we want.
1661 */
1662 for (i = 0; i < timer_count; i++) {
1663 timer = &timers[i];
1664
1665 frame = arch_timer_mem_find_best_frame(timer);
1666 if (!best_frame)
1667 best_frame = frame;
1668
1669 ret = arch_timer_mem_verify_cntfrq(timer);
1670 if (ret) {
1671 pr_err("Disabling MMIO timers due to CNTFRQ mismatch\n");
1672 goto out;
1673 }
1674
1675 if (!best_frame) /* implies !frame */
1676 /*
1677 * Only complain about missing suitable frames if we
1678 * haven't already found one in a previous iteration.
1679 */
1680 pr_err("Unable to find a suitable frame in timer @ %pa\n",
1681 &timer->cntctlbase);
1682 }
1683
1684 if (best_frame)
1685 ret = arch_timer_mem_frame_register(best_frame);
1686out:
1687 kfree(timers);
1688 return ret;
1689}
1690
1691/* Initialize per-processor generic timer and memory-mapped timer(if present) */
1692static int __init arch_timer_acpi_init(struct acpi_table_header *table)
1693{
1694 int ret, platform_timer_count;
1695
1696 if (arch_timers_present & ARCH_TIMER_TYPE_CP15) {
1697 pr_warn("already initialized, skipping\n");
1698 return -EINVAL;
1699 }
1700
1701 arch_timers_present |= ARCH_TIMER_TYPE_CP15;
1702
1703 ret = acpi_gtdt_init(table, &platform_timer_count);
1704 if (ret)
1705 return ret;
1706
1707 arch_timer_ppi[ARCH_TIMER_PHYS_NONSECURE_PPI] =
1708 acpi_gtdt_map_ppi(ARCH_TIMER_PHYS_NONSECURE_PPI);
1709
1710 arch_timer_ppi[ARCH_TIMER_VIRT_PPI] =
1711 acpi_gtdt_map_ppi(ARCH_TIMER_VIRT_PPI);
1712
1713 arch_timer_ppi[ARCH_TIMER_HYP_PPI] =
1714 acpi_gtdt_map_ppi(ARCH_TIMER_HYP_PPI);
1715
1716 arch_timer_populate_kvm_info();
1717
1718 /*
1719 * When probing via ACPI, we have no mechanism to override the sysreg
1720 * CNTFRQ value. This *must* be correct.
1721 */
1722 arch_timer_rate = arch_timer_get_cntfrq();
1723 ret = validate_timer_rate();
1724 if (ret) {
1725 pr_err(FW_BUG "frequency not available.\n");
1726 return ret;
1727 }
1728
1729 arch_timer_uses_ppi = arch_timer_select_ppi();
1730 if (!arch_timer_ppi[arch_timer_uses_ppi]) {
1731 pr_err("No interrupt available, giving up\n");
1732 return -EINVAL;
1733 }
1734
1735 /* Always-on capability */
1736 arch_timer_c3stop = acpi_gtdt_c3stop(arch_timer_uses_ppi);
1737
1738 /* Check for globally applicable workarounds */
1739 arch_timer_check_ool_workaround(ate_match_acpi_oem_info, table);
1740
1741 ret = arch_timer_register();
1742 if (ret)
1743 return ret;
1744
1745 if (platform_timer_count &&
1746 arch_timer_mem_acpi_init(platform_timer_count))
1747 pr_err("Failed to initialize memory-mapped timer.\n");
1748
1749 return arch_timer_common_init();
1750}
1751TIMER_ACPI_DECLARE(arch_timer, ACPI_SIG_GTDT, arch_timer_acpi_init);
1752#endif
1753
1754int kvm_arch_ptp_get_crosststamp(u64 *cycle, struct timespec64 *ts,
1755 struct clocksource **cs)
1756{
1757 struct arm_smccc_res hvc_res;
1758 u32 ptp_counter;
1759 ktime_t ktime;
1760
1761 if (!IS_ENABLED(CONFIG_HAVE_ARM_SMCCC_DISCOVERY))
1762 return -EOPNOTSUPP;
1763
1764 if (arch_timer_uses_ppi == ARCH_TIMER_VIRT_PPI)
1765 ptp_counter = KVM_PTP_VIRT_COUNTER;
1766 else
1767 ptp_counter = KVM_PTP_PHYS_COUNTER;
1768
1769 arm_smccc_1_1_invoke(ARM_SMCCC_VENDOR_HYP_KVM_PTP_FUNC_ID,
1770 ptp_counter, &hvc_res);
1771
1772 if ((int)(hvc_res.a0) < 0)
1773 return -EOPNOTSUPP;
1774
1775 ktime = (u64)hvc_res.a0 << 32 | hvc_res.a1;
1776 *ts = ktime_to_timespec64(ktime);
1777 if (cycle)
1778 *cycle = (u64)hvc_res.a2 << 32 | hvc_res.a3;
1779 if (cs)
1780 *cs = &clocksource_counter;
1781
1782 return 0;
1783}
1784EXPORT_SYMBOL_GPL(kvm_arch_ptp_get_crosststamp);